The present invention relates to apparatus for manipulating rod-shaped articles, especially articles which constitute or form part of rod-shaped smokers' products. More particularly, the invention relates to improvements in apparatus which can be used with advantage for severing and shuffling of two or more different types of rod-shaped filter material in order to form composite filter mouthpieces for cigarettes, cigars or cigarillos.
Composite filter mouthpieces are normally produced by moving two or more types of prefabricated filter rods sideways, severing the filter rods so that each thereof yields shorter rods, staggering and shuffling the shorter rods of each type, shuffling the different types of shorter rods to form a continuous rod wherein shorter rods of different types alternate with each other, draping the continuous rod into a web of artificial cork or other wrapping material, and subdividing the wrapped rod into discrete mouthpieces each of which contains rod-shaped sections consisting of different filter materials, e.g., plugs consisting entirely of acetate fibers and plugs which contain acetate fibers and granulae of charcoal. The filter mouthpieces are thereupon assembled with plain cigarettes, cigars or cigarillos to form therewih filter-tipped smokers' products.
A drawback of presently known apparatus for the production of composite filter mouthpieces is that such apparatus comprise a large number of drums, knives, spreading cams and other components. This contributes to the bulk and cost of such apparatus. Moreover, mechanical shifting of relatively short filter rods presents many problems, especially at elevated speeds, and is likely to result in deformation of and/or other damage to the articles.
Commonly owned German Pat. No. 1,116,128, granted May 3, 1962, discloses an apparatus for severing filter rods by means of a rotary knife which is mounted between wedge-like flanges serving to increase the gap between the sections of the severed rod so as to provide room for insertion of rod-shaped filter plugs of a different type. The patent further mentions the possibility of using a wedge-like cam downstream of the cutting station and/or of employing nozzles for discharge of compressed air in order to increase the width of the gap between the sections of a severed filter rod beyond that width which is achieved by placing the knife between two wedge-like flanges. A drawback of the patented apparatus is that the circumferential portions of the flanges must be machined with an extremely high degree of accuracy. Moreover, the edges at the circumferences of the flanges are subjected to extensive wear, especially if the filter rods contain granulae of charcoal or other hard material, and the flanges invariably affect the appearance of the corresponding end faces of the filter rod sections. Furthermore, the aforementioned cams and nozzles must be provided in addition to the flanges, and the ultimate width of the gaps betwen the sections of successive pairs often deviates from an optimum width. Therefore, the patented apparatus failed to gain acceptance in the tobacco processing industry.